I agree as well. Unfortunately where I live there just isn't the opportunity to handle a wide variety of glass, and I don't have the means to buy much at all. There also aren't many people here to learn directly from. Since it's true that books and the internet aren't very good at describing typical characteristics of glass or differences among glass by different makers, I look to those who have handled the stuff enough to be able to tell me something about it...which is one reason forums like this one are so valuable. Plus you can ask questions!*
Though books and the internet aren't a substitute for handling glass, the vast range and quantity of photos out there can, I believe, give one an "appreciation of dimensions, thickness of glass, coarseness of workmanship or manufacture, or indeed, the subtle finesse of the great makers, engravers" even if one never has the opportunity to handle a piece by a particular maker. However, it helps greatly if one has handled a lot of other glass, seen LOTS of photos, has a good understanding of glass manufacture and decoration, and especially important, an eye for detail. There are plenty of people out there who've handled a lot of glass and still don't know much about it.
Kristi, I've asked a number of times if Legras has been reproduced. No one seems to think so. The only items I use as reference are those that are marked Legras. Ebay isn't my only source of course. I've been looking a pics all over the net. Some of the legras stuff is quite crude. Some of it is very intricate.
I didn't mean to suggest that you were going about your "research" (in quotes because I've been chided in the past for using the term too loosely) blindly or indescriminately. It was a general comment more than one directed at you.
"Reproduced" to me means a piece/pattern/design has been directly copied. Even if it is the case that Legras hasn't been directly reproduced (besides their cameos), there are pieces out there that are signed Legras that weren't made by them. This page shows one fake signature:
http://www.libertys.com/glass.htm - not a huge sample size, but when you consider that every other major art glass maker has signed fakes, why would you expect Legras to be any different?
*One thing I've long wondered about is whether large (covering nearly the whole bottom) ground and polished pontils are typical of French makers (or a specific one).